The present invention relates to a putter which serves to prevent a golfer from being affected by an optical illusion which tends to occur when the golfer putts a ball to a target.
As means for assisting a golfer hit a straight putt, provided is a putter of which head is provided with a line slot extending through a center of the head and perpendicular to a putting face of the putter, and provided is a putter including a head with two white dot graphics in side by side relation in a hitting direction on its surface. The white dot graphics have the same contours as balls, respectively. These putters allow a golfer to align easily an orientation of a head of a putter to a target. However, a golfer usually looks at the target again for reconfirmation just before putting a ball to the target. At that time, the golfer's eyes often arrive at a point which is deviated to the left from an actual target. The golfer is tricked into believing that the reason why his eyes arrive at the point deviated to the left from the target is that he takes his address position incorrectly to the left, corrects and adjusts his address position to the right, and putts a ball. Then, the ball putted is deviated to the right from the target.
In order to solve this problem, Patent Document 1 discloses a putter which has an L-shaped pendulum to its slit. However, according to this putter, at address, a golfer must place a putter head horizontally, and the golfer cannot hold the putter at a proper angle so as to fit the lie angle of the putter which varies among golfers.    [Patent Document 1] JP-A, 2007-160033